|
Post by bear on Sept 17, 2022 18:45:35 GMT -7
Egnater Tweaker 15W amp has a switch for 230V Euro power and 110V for the Americas 😎
|
|
|
Post by higs on Sept 18, 2022 9:11:31 GMT -7
Egnater Tweaker 15W amp has a switch for 230V Euro power and 110V for the Americas 😎 I'm not sure about specific models, but they also allow you to run them at really low wattages. I think they use knobs instead of switches and one lets you blend between different tube types. I'd try one out.
|
|
|
Post by higs on Sept 18, 2022 9:13:37 GMT -7
I'm going to work on cleaning up the upstairs today. It's a freaking wreck and I'm missing making noise. I haven't even listened to a record in months.
|
|
|
Post by bear on Sept 23, 2022 16:50:46 GMT -7
Still has a funky overdrive when I put a higher gain 12AX7 tube in the preamp and hit low notes. I will have to pull up a calculator that works with the circuit diagram and start testing voltages to really get to the bottom of that, so I am saving it for another day, slapping a 12AT7 in there for now, and slamming the front end with hot pedal signals to get my crunch fix. part of it was the tube socket being loose. Bent the pins and huzzah we're back in business. Still not crazy about the slight fizz I'm hearing but it's not really perceptible and especially not with a cranked op amp Muff running into it Still toying with the amp. Tone stack is good but I realized that the original filter caps are way too big. 100uF when the max for a 5Y3 tube should be like 32uF. So that's what's next, copying design cues from Fender Tweed Champ filter capacitors. I have to wing it because the Ricktone Cupid schematic has a solid state rectifier, but it is a single ended amplified like the Champ with one power tube so the designs are comparable.
|
|
|
Post by bear on Sept 23, 2022 17:45:58 GMT -7
Finished my friends Strat also. New flat pole alnico pickups, total rewire, and full setup. I did the Lindy Fralin blender control instead of the second tone knob. Now the control varies between bridge and neck pickup so you can blend them in with any pickup setting.
|
|
|
Post by bear on Sept 24, 2022 17:56:49 GMT -7
part of it was the tube socket being loose. Bent the pins and huzzah we're back in business. Still not crazy about the slight fizz I'm hearing but it's not really perceptible and especially not with a cranked op amp Muff running into it Still toying with the amp. Tone stack is good but I realized that the original filter caps are way too big. 100uF when the max for a 5Y3 tube should be like 32uF. So that's what's next, copying design cues from Fender Tweed Champ filter capacitors. I have to wing it because the Ricktone Cupid schematic has a solid state rectifier, but it is a single ended amplified like the Champ with one power tube so the designs are comparable. it occured to me to look up a 5F1 circuit with a 6AQ5 tube (instead of the similar 6V6) instead of guessing and testing parts to get the voltage right. This is a step in the right direction, but I am still dealing with a 5Y3 rectifier tube when the schematics are solid state diodes so I will have to borrow that from the Fender design. So I'm going to rework the preamp to get more overdrive out of it and use a 12AX7 instead of the original 12AT7 design which has like 70% of the gain. And I get to make some design choices to tweak the voicing such as bass tightness and the negative feedback resistor which affects the way it distorts. Nerdin out over here and I think Im about ready to order parts.
|
|
|
Post by EllisD on Sept 26, 2022 10:38:36 GMT -7
Shopping for patch bays. Hopefully that gets rid of the web of cables I have weaved
|
|
|
Post by bear on Sept 27, 2022 15:05:19 GMT -7
|
|
|
Post by bear on Sept 27, 2022 15:27:30 GMT -7
I think I got this amp sorted out. I'm using a curious power tube - the 6AQ5. Specs wise it is the same as a 6V6, common in amps like the Fender Princeton or Deluxe, but in a smaller glass housing like the EL84 (Vox AC30, Marshall 18W). Fender even put them in the 70s Musicmaster amps and there even is a 6V6 and a 6AQ5 production versions. In the 50s Champ circuit I'm working with, people routinely run the tube bias with lots of voltage and current to give that sweet overdrive sound from saturating the tube.
The 6V6 is rated for 350 volts with some exceeding specs in guitar amps as high as 400, but the 6AQ5 has a smaller plate with is spec'd for 250 to 275. So I'm fretting about making the power right and ordering enough parts to tweak it because I didnt have a diagram but the whole time the power section is already good and I was wasting my time! I just need to improve the preamp section that the guitar signal runs into.
|
|
|
Post by EllisD on Sept 28, 2022 10:12:56 GMT -7
Just ordered both of these, hopefully I should never have to rewire anything but these two devices ever again.
|
|
|
Post by bear on Sept 28, 2022 13:06:31 GMT -7
Awesome!
|
|
|
Post by bear on Sept 29, 2022 5:13:21 GMT -7
I finally figured that damn amp out. The preamp tube was wired backwards. It's a dual triode and the 2nd side was wired with the resistors for the 1st side. Now it sounds fat and I'm gonna tune it even more by raising the voltage on the tube and see what happens once I get the parts. The 220k ohm ones aren't letting enough juice in!
|
|
|
Post by bear on Sept 29, 2022 15:33:37 GMT -7
Oh hell yeah. It roars. Gobs of distortion and that brown tweed sound. Probably going to dial the preamp back more. Shocked myself again too because I'm an idiot. I always work one handed in the amp to avoid competing the circuit through my body, but if you're holding the guitar and your other hand is on the strings, then guess what? You're connected to the ground. D'oh!
I eliminated the weird high frequency noise by connecting the tone and volume controls to a common ground, shortened an unnecessary high voltage wire, decreased the bass by limiting the coupling and bypass capacitor sizes yadda yadda mo' betta.
|
|
|
Post by bear on Oct 7, 2022 15:45:15 GMT -7
Called the Fender factory in Corona to see if I could check it out and no one answered. I might just go hit up G&L instead. They're at the old factory on Fender Ave in Fullerton
|
|
|
Post by bear on Oct 11, 2022 14:15:09 GMT -7
I'm in Corona. Now to see if they let me in.
|
|
|
Post by bear on Oct 11, 2022 14:20:39 GMT -7
Womp womp
|
|
|
Post by bear on Oct 14, 2022 11:31:08 GMT -7
Tweaked the amp some more (finally). Upped the voltage to the power tube and it made the distortion mo betta and then I guiced the preamp tube. A 12AX7 is a dual triode meaning it has two amplification sides on the tube. Triode refers to the number of electrodes so there is a pair of those three parts: the plate (anode) gets high voltage DC and it pulls electrons from the cathode across the grid. The guitar signal does a little dance on the grid and the electrons amplify the signal. Magic. So, it happens twice in a tube but you don't have to make the amplification identical on the sides. Adjusting the amount of current that goes to the tube changes how it amplifies the signal and since we're dealing with flipping the audio waves and AC/DC then making the distortion asymmetrical creates a more complex and harmonically rich waveform output. So I biased the A stage with a higher current ("hotter" signal) and then run it into a middle of the road bias for the B side and now I have a smoother and creamier sounding overdrive instead of symmetrical clipping. (Clipping is when the wave form is slammed into your circuit and exceeds its capacity so the top and bottoms of the sound wave get clipped off and it distorts.) Sound is subjective of course so there is no wrong answer but man I think it sounds great now.
|
|
|
Post by bear on Oct 17, 2022 20:38:16 GMT -7
Applied the new preamp design to my own Fender Champ 5F1 amp and I love it even more. Lots of grit once you get past halfway on the volume, especially so because the power tube is running at 100% dissipation and I think the other one is only at 80%. They are voiced more like a lead channel instead of a big fat 50s Tweed sound, similar to what Jim Marshall did when reworking the Fender Bassman into the Marshall JTM-45. I reduced the bass and incorporated that creamy, asymmetrical distortion by having different gain structures on the A and B sides of the preamp tube. Love it. I just tore the other apart and am doing a total preamp overhaul to reduce a nagging 60hz electrical hum from the AC wall voltage.
|
|
|
Post by bear on Oct 19, 2022 13:45:56 GMT -7
Finally done. Thank the maker because I was losing my mind over this amp. I could not figure out the hum source until I tried putting a voltage dropping resistor between the power tube and preamp that i left out because i wanted moar voltage. Apparently it filtered noise too because that solved the issue. I wouldnt have tried it either except i tried leaving it out between the rectifier tube and power tube a week ago and it straight up didnt work. What a relief. I rewired the whole preamp, changed the speaker jack, redid the grounding scheme. Now I am getting a higher rectifier voltage too, which is good, I think 🤔. I was planning on using an older 5Y3G rectifier tube which is rated for 275 volts but now we're coming in over 300, so I put the usual 5Y3GT in which is good for like 395 volts. Time to list for sale! Super ultra custom tweaked modded hand crafted artisenal toob mojo.
|
|
|
Post by bear on Oct 20, 2022 14:03:43 GMT -7
look how tidy that is. eat your heart out Silvertone
|
|